For the fifth year in a row, Los Angeles is No. 1 among U.S. cities for the number of Energy Star-certified buildings with 528 in its portfolio.

It is followed by Washington, D.C., with 462 buildings, Chicago with 353 buildings (growing on average 32 percent a year) and New York with 325 buildings.

There are now more than 20,000 Energy Star-certified buildings in the U.S. This saves a total of $2.7 billion in annual utility bills. It also prevents more than 2 million homes' worth of greenhouse gas emissions.

In 2012 alone more than 8,200 buildings earned Energy Star certification. The breakdown is below:

Here are the top 25 cities.

Of course, these cities are also adding LEED-certified buildings, and Washington, D.C., tops that list for LEED square footage per capita. It will perform even better going forward, now that the city requires all buildings to measure and report on energy and water consumption. New York, San Francisco, Seattle, Philadelphia and Austin all require buildings to report on energy use. 

To earn Energy Star certification, commercial buildings must perform in the top 25 percent of comparable buildings nationwide, as verified by a professional engineer or a registered architect.

On average, certified buildings consume 35 percent less energy and greenhouse gas emissions. Fifteen kinds of commercial buildings can earn Energy Star, including office buildings, K-12 schools, retail stores, hospitals, manufacturing plants and houses of worship. Launched in 1992 by the Environmental Protection Agency,  Energy Star is a market-based program that cuts greenhouse gas emissions through energy efficiency.

Energy use in commercial buildings accounts for 17 percent of U.S. greenhouse gas emissions at a cost of more than $100 billion per year.

In addition to certifying commercial buildings, the Energy Star label is found on 1.4 million new homes and 65 different product categories, saving $230 billion on utility bills and preventing the release of more than 1.8 billion metric tons of greenhouse gas emissions over the past 20 years.

You can search for Energy Star buildings here.   

Photo of Los Angeles skyline — with at least one Energy Star-certified building visible — provided by Videowokart via Shutterstock.